var ans,m,n,tot,i,j,ll,rr:longint;
    d,t,v,p,l,x:array[1..100] of longint;
    next,h,point,w:array[1..10000] of longint;
    bj:array[1..100] of boolean;
function min(a,b:longint):longint;
  begin
    if a<b then exit(a) else exit(b);
  end;
procedure link(a,b,i,p:longint);
  begin
    next[i]:=h[a]; h[a]:=i; point[i]:=b; w[i]:=p;
  end;
procedure spfa(s:longint);
  var i,j,k,l,r:longint;
      use:array[1..100] of boolean;
      q:array[1..100] of longint;
  begin
    fillchar(d,sizeof(d),100);
    fillchar(use,sizeof(use),false);
    fillchar(q,sizeof(q),0);
    l:=0; r:=1; d[s]:=p[s]; use[s]:=true; q[r]:=s;
    repeat
      l:=(l+1) mod 100;
      i:=q[l]; j:=h[i];
      while j<>0 do begin
        k:=point[j];
        if (d[i]+w[j]<d[k])and(bj[k]) then begin
          d[k]:=d[i]+w[j];
          if not use[k] then begin
            use[k]:=true;
            r:=(r+1) mod 100;
            q[r]:=k;
          end;
        end;
        j:=next[j];
      end;
      use[i]:=true;
    until l=r;
  end;
begin
    readln(m,n);
    for i:=1 to n do begin
      readln(p[i],l[i],x[i]);
      for j:=1 to x[i] do begin
        readln(t[j],v[j]);
        inc(tot); link(t[j],i,tot,min(p[i],v[j]));
      end;
    end;
  ans:=maxlongint;
  ll:=l[1]-m; rr:=l[1];
  while ll<=l[1] do begin
    fillchar(bj,sizeof(bj),false);
    for j:=1 to n do if (l[j]>=ll)and(l[j]<=rr) then bj[j]:=true;
    for j:=1 to n do
      if bj[j] then begin
        spfa(j); if d[1]<ans then ans:=d[1];
      end;
    inc(ll); inc(rr);
  end;
  writeln(ans);
end.